An assertion-based monitoring system was implemented to enforce the operation of a FPGA coprocessing engine, which is part of a dependable workstation. The monitor was built in VHDL using simple state machines. Concurrent error detection is an important aspect in dependable workstations helping to prevent the propagation of errors within the system. The functionality of the implemented monitoring component does not interfere with the performance of the workstation and ensures high system availability. The monitor checks for PCI protocol and application errors based on the forensic analysis of a dependable workstation with FPGA-based co-processing support.